When the user changes the field value (name in this example), it would be nice if hitting ENTER would apply the name, and take the focus highlight off. The other field is being applied dynamically, so the assumption is that this one is as well.

p.s. this is the pop-over that needs to be updated to support Expression instead of Name.

Clarified behavior

• "Enter" = apply and close in every case, even when the dropdown is focused (but not open)
• "ESC" = close without apply in every case
• "Enter" when dropdown is focused, apply and close
• "Space" open the data type dropdown
• "Arrow keys" navigate in dropdown